160 STRUCTURE AS ARCHITECTURE

▲ 7.60 Faculty of Law Building, Cambridge, England, Sir Norman Foster and Partners, 1996. The light-weight façade structure contrasts with the concrete columns.

▲ 7.59 Lightened by the use of tension- ties, the curved beams arch over a computing area.

▲ 7.61 Raking concrete columns with a ‘softening’ sand-blasted finish.

Environment (CUE), London, is a consequence of its ecologically sus- tainable design, rather than any other reason. Primary structural mem- bers are hollow, exemplifying the highest possible level of structure and services integration (Figs 7.62 and 7.63).16Structural members function as air conduits in this naturally ventilated building. Column and beam cross-sections are therefore larger than expected for a building essen- tially of domestic scale, even accounting for the weight of its turf roof. Warm air is extracted through circular penetrations in the triangular cross-section plywood web-beams, and channelled horizontally to columns. Columns that terminate above roof height as chimneys, move air vertically. For such a relatively small building the structural members appear heavy.

Plain to decorative

LaVine describes the exterior ground floor columns of the iconic Villa Savoye, Paris (Figs 7.64 and 7.65), as ‘classically placed but unadorned, slender cylinders, reflecting a technological stance of the twentieth cen- tury’.17Consistent with the plainness of the columns, the floor beams are rectangular in both cross-section and elevation. Their widths that equal the diameters of the columns and result in tidy beam–column junctions, are evidence of attention to detailing that does not seek attention.

A more recent building illustrates the potential for structural detailing with decorative qualities to enhance architecture. The ribbed concrete

STRUCTURAL DETAILING 161

▲ 7.62 Centre for Understanding the Environment (CUE), Horniman Museum, London, England, Architype, 1997. Front façade with chimney-columns.

floor soffits of the Schlumberger Extension building, Cambridge, are reminiscent of the isostatic ribs indicating lines of constant stress in the concrete slabs designed by Pier Luigi Nervi in the 1950s (Fig. 7.66). Floor construction at Cambridge was achieved using permanent ferro- cement formwork, subsequently infilled with reinforced concrete. Continuing the ribbed theme on the façade that is achieved by the closely spaced tubular columns, the sculptural qualities of the concrete ribs enrich the visual appearance of the cantilevering soffit.

The exquisitely detailed wrought-iron beams of the Bibliothèque Sainte-Geneviève, Paris, also provide a fine example of decorative structural detailing (Fig. 7.67). A flowing pattern resembling stars and sickles replaces the standard diagonal web members that usually join top and bottom chords. Here, structural detailing and artistry merge in these much admired members.

The Hamburg Museum Courtyard Canopy, Hamburg, provides the final example of decorative structural detailing. A fully glazed grid-shell structure roofs an L-shaped courtyard (Fig. 7.68). Pairs of 6 mm diam- eter pre-tensioned cables form a triangular mesh to stiffen the orthog- onal grid, fabricated from 60 mm by 40 mm steel section. Commenting upon the architectural qualities of the canopy, Holgate explains:

The problem of diagonal bracing members competing for visual interest with those of an orthogonal grid has been solved by the lightness of the prestressed cables which here form a delicate accompaniment to the stronger lines of the steel slats. As usual, much thought has been given to the details both from an architectural and technical standpoint. These are an essential element in the success of the roof. The project is an excellent 162 STRUCTURE AS ARCHITECTURE

▲ 7.64 Villa Savoye, Paris, France, Le Corbusier, 1929. The front and a side elevation.

▲ 7.65 Plain exterior column and beam detailing.

▲ 7.66 Schlumberger Extension building, Cambridge, England, Michael Hopkins and Partners, 1992. Exposed ribbed soffits around the perimeter.

outcome of the quest for lightness, delicacy, minimalism, and unobtrusive- ness in structure.18

While the designers tried to minimize the visual impact of most details, one in particular stands out. In three locations, and most importantly where the two arms of the L-shape meet in the corner and the roof bulges beyond its normal barrel forms, additional tensile stiffening main- tains the cylindrical geometry. Vertical fans of cables radiate upwards from a central plate suspended high above the courtyard floor and held in physical and visual equilibrium by an inverted V-shaped tension cable. A stainless-steel plate whose roundedness echoes that of the vaulted form above, its shininess, the fan-like layout of cables and intricacy of connectors between plate and lower cable, all create an impression of a necklace-like piece of jewellery (Fig. 7.69).

SUMMARY

Having defined structural detailing as the configuration, shaping and fin- ishing of members and their connections, the chapter explores how detailing makes significant architectural contributions to buildings. First, it examines the expressive and responsive nature of structural detailing. An analysis of observed structural details suggests that most express or respond to some aspect of the building of which they are part. Examples illustrate details that relate to architectural form, build- ing function, materiality and construction, and structural actions.

STRUCTURAL DETAILING 163

▲ 7.67 Bibliothèque Sainte-Geneviève, Paris, France, Henri Labrouste, 1850. Curved iron beams over the reading room.

▲ 7.68 Hamburg Museum Courtyard Canopy, Hamburg, Germany, Von Gerkan, Marg and Partner, 1989. General view of the canopy.

Detailing that expresses structural actions can either express bending or other stress, or articulate structural connectivity like clamping or clasping. Some sources of detailing inspiration lie completely outside the building and its programme.

The second and final section of the chapter illustrates the huge diversity of the aesthetic qualities of structural detailing. Each detail suggests its own architectural reading and influences its surrounding architecture. Detail- ing qualities are categorized into the following four broad groupings – refined to utilitarian, simple to complex, lightness to heaviness, and plain to decorative.

The multiplicity of examples, the sheer diversity of expressive and responsive details, and the different aesthetic qualities of details indicate the enormous potential for exposed structural detailing to enhance the realization of architectural concepts.

REFERENCES AND NOTES

1 Ogg, A. (1987). Architecture in Steel: The Australian Context. The Royal Australian Institute of Architects, p. 44.

2 Louis Khan, quoted in Frampton, K. (1995). Studies in Tectonic Culture: The

Poetics of Construction in Nineteenth and Twentieth Century Architecture.

Massachusetts Institute of Technology, p. 227.

3 Jones, F. (1999). ‘Outside the Pale’: The Architecture of Fay Jones. Department of Arkansas Heritage, pp. 48 and 54.

4 Balmond, C. (2002). informal. Prestel, p. 88.

5 Murphy, J. (1987). A Grand Gateway. Progessive Architecture, Nov., pp. 95–104.